The goal of this project is to determine how the architecture of the spinal cord changes after chronic sensory denervation, and to correlate these changes with autonomy, which is generally accepted as a model of a central pain state, and with changes in the synaptic patterns on spinothalamic cells. The hypotheses being tested are that synaptic numbers in the dorsal horn will drop after rhizotomy, that at some point after this synaptic numbers will rise (sprouting) perhaps back to normal levels, that this sprouting will be manifest by an increase in synaptic numbers, a change in the synaptic patterns on spinothalamic cells and a change in the architecture of the spinal cord, and that the onset of sprouting will be correlated with the appearance of autonomy. If these hypotheses turn out to be correct, then experimental procedures can be developed that hopefully will modify the sprouting and the appearance of autonomy. Such data should impact on the dysesthesias that often plague human victims of sensory denervation.